What's so bad about getting a feel for someone and hiring them on a probationary basis? See how they go on discrete - but real - tasks for a week or two, and then make the call on going forward or not. It's how most hiring has always worked (and continues to work) in almost all other fields.
Also, re technical questions, I don't think anyone is saying that you can't ask any technical questions whatsoever, I think the concern is about giving people abstract, theoretical CS problems that will never actually come up on the job, on the very iffy assumption that their performance while being asked to dance for a committee in high-pressure job interview situation is going to be reflective of their actual skills. (And more broadly, that a good programmer must be quick on their feet with schoolboy-style CS puzzles that are basically irrelevant to most roles.)
I have no idea if this is accurate or not, but there is this general stigma from both sides that "no decent programmer worth hiring fulltime in hotter markets/companies would/should agree to a contract/temp/trial job".
I think de-facto fulltime jobs i've seen end up kind of like that - if you don't work out in X months, nobody will shed a tear about kicking you out - but this is still perceived as a more expensive operation that should be avoided by having a "proper" interview process. On which nobody can ever agree, but that's the sentiment.
Also, re technical questions, I don't think anyone is saying that you can't ask any technical questions whatsoever, I think the concern is about giving people abstract, theoretical CS problems that will never actually come up on the job, on the very iffy assumption that their performance while being asked to dance for a committee in high-pressure job interview situation is going to be reflective of their actual skills. (And more broadly, that a good programmer must be quick on their feet with schoolboy-style CS puzzles that are basically irrelevant to most roles.)